Apparatus for cutting sheet material



Feb. 20, 1940. P R AL 2,191,148

APPARATUS FOR CUTTING SHEET MATERIAL Filed Jan. 20, 1939 ALBERT c PERBAL ATTO EY Patented. Feb. 20, 1940 PATENT rrics APPARATUS "FOR CUTTING SHEET 1 MATERIAL Albert C. Perbal, St. Louis, Mo., assignor of onc half to Lawrence H.

Application January 20,

. 18 Claims.

This invention relates to apparatus for cutting sheet material into narrow strips or ribbons and more particularly to improvements in stripping apparatus of the type that employ twocoacting sets of shearing discs mounted on parallel drive shafts.

The invention resides in the novel manner in which the shearing discs are mounted on their respective shafts, the discs being loosely retained on the shafts to provide for equalization of contact pressures and yet which, by reason of the manner in which they are mounted, maintain themselves in proper operating position without requiring additional agencies for this purpose that tend to restrict their freedom of, adjusting movement on the shafts. l In certain early forms of'disc type stripping. machines the shearing discs were rigidly secured to the shafts. Because of the difficulty of adjusting and equalizing the contact pressures betweencoacting discs, and of maintaining such the cutting discs, in the form of annularwashers,

are yieldingly mounted on their shafts, a rubber sleeve, or rubber spacers disposed'between the discs being employed to maintain them in proper operating position. This method has likewise failed to provide a practical solution to the problem because it does not eliminate the tendency of the discs to assume angular positions and to creep along the shafts, a tendency that has the effect of rendering non-uniform thecontact pressures between the sets of coacting discs.

This undesirable tendency is believed to be inherent in the discs because of the character of their mounting which gives rise to a condition of unstable equilibrium. Thus, when a relatively thin annular washer is loosely disposed on a rotating rod or shaft the washer will begin to revolve in a plane normal to the shaft. However, any slight displacement of the washer. from the. normal plane causes forces to be set up which tend to draw the washer into the plane of the shaft, and the washer then tends to creep or travel along the shaft. A well known example of this phenomenon is found in machine shops wherein horizontal power shafts are maintained clean and bright by the simple expedient of a washer loosely disposed thereon, the washer automatically traveling back. andforth along, the shaft. In the examples referred to it will be Cohn, St. Louis, Mo.

1939, Serial No. 251,870 (01. 164-60) noted that the shaft contacts the inner al edge of the washer;.

However, wh enra thin disc or washer is rotatingly supported at its outer peripheral edge, as may be accomplished by placing the'disc on edge on the inner surface of a hollow rotating body, suchas a tube, .the disc will be maintained in a condition of stable equilibrium while it revolves, and forces tending .to upset the disc will be opposed by other natural forces that tend to maintain the disc in a plane normal to its axis of rotation. .Moreover, there is no tendency of the disc to travel laterally as in the case of the an.- nular Washer loosely disposed on a revolving shaft.

An object of my invention is attained by applying the above mentioned phenomenon to the cutting discs of a stripping machine wherein the discs are floatingly mounted and self-adjustable on their shafts,-yet exhibit no undesirable tendency to tilt or creep laterally.

The advantages of my improved stripping ap- I periphen.

to various kinds of sheet materialrsheet material such as Cellophane and very thin metalwhich heretofore was found difficult to cut smoothly and evenly by apparatus of this general type is readily and satisfactorily acted upon by the apparatus of my invention. Resharpening of the discsis seldom necessary.

' Other objects and advantages will appear from the following description and accompanying drawing which illustrate an operative embodiment of my invention.

In the drawing, Fig. 1 is a front elevation of a cutting machine embodying the features of my invention; Fig. 2 isan enlarged detailed sectional view taken in the plane of the axes of the shafts; Fig. 3 is a transverse sectional view taken on line 3-3 of Fig. 2, and Fig. 4 is a sectional view showing fragmentary portions of a cutting disc and retainer members inseparated relation.

Referring now by characters of reference to the drawing, l0 and H designate, respectively, upper and lower parallel shafts upon which the cutting discs are mounted. These shafts are journalled in suitable bearing blocks l3 and i4 carried by spaced supports it which form rigid extensions of a base plate it. A pair of gears H and I8, fixed to the projecting ends of shafts id and II, are engaged with each other to cause theshafts to revolve in unison under the influence of suitablejdriving means (not shown).

Loosely mounted on each of the shafts I0 and II in a manner and by means hereinafter described are a plurality of cutters or slitters in the form of annular discs l9 which, in the present example, are of thickness equal to the width j of the strips to be cut thereby. The discs on one shaft are arranged in intercalated shearing relation with respect to the discs of the other shaft, each disc with the exception of the end discs cooperating with and being disposed between two adjacent discs on the opposite shaft. Since the and preferably are alike in all material respects descriptive reference will be made to only one of the disc assemblies.

by means of keys 22 seated in .complemental key.-

ways formed in the shaft and collar portions. The members 2%! are confined between end members 23 and the assembly is tightly held together and against endwise displacement'on the shaft by collars or looking nuts 24 threaded on the shaft.

The members 20 and 23 are preferably formed with annular flange portions 25 (Fig. 4) that extend radially from the collar portions 2|, the

flange portions 25 being of reduced thickness as compared to the thickness or axial dimension of collar portions 2|. Formed at the outer peripheral margin of flange portion 25 is an annular rim portion 26, also of lesser thickness or axial dimension than that of the collar portion 2|, the rim 26 forming laterally projecting flanges 21.

As best'appears from Figs. 2 and 4, the retainer members 2d coact to define a series of uniformly spaced annular grooves or channels 28 which terminate inwardly in annular spaces 29 of enlarged width as compared to the width of the channels 28. Otherwise stated, the channels 28 are undercut to form the spaces 29, the said channels serving to receive the inner peripheral portions of the cutting discs l9 and loosely to position the same. i

The cutting discs it have annular grooves 30 formed in their opposite side surfaces that define relatively thin annular neck portions 3| which fit loosely within the channels 28, the neck'portions 3| terminating inwardly in annular rim portions 32 that produce the laterally projecting flanges 33, the rim portions 32 fitting loosely in the channel spaces 29. The diameter of the openings. 34 in the cutting discs is appreciably greater than the outer diameter of collar portions 2|, and likewise, the internal diameter of the flanges 21 is appreciably greater than the outer diameter of disc flanges 33, whereby the discs are translatable to a limited degree radially with respect to the retainer members 2%. Of importance however, is the fact that the difference between the inner diameter of the'flange 2'7 and the outer diameter of disc flange 33 is less than the difference be tween the diameter of the disc opening 3d and the outer diameter of collar portion 2|. When the aforesaid relative dimensions are adhered to, rolling contact of the cutting disc will occur at the inner surface of flange 21 and not at the outer surface of collar portion 2|. This provision and result is illustrated in Figs. 2 and 3 where it'will The members 2|) appear that the rim portions 32 of the cutting discs contact the inner surfaces of the rim portions 26 of the retainer members at a point indicated at 35, while at the side of the shaft diametrically opposite such point a space 36 occurs between the outer collar surface and. the inner peripheral margin of the cutting disc.

'Thusit will appear that the members 20 form a jcagle-likexstructure in which the inner peripherarpormo ns of the cutting discs are loosely retained, and the discs are adapted for rolling contwo sets of discs and the means by which they are retained on their respective shafts may be tact on races that face toward the axis of rotatio'n iformed on inner surfaces of the aforesaid cage structure. Since the cutting discs are translatable to a limited degree both laterally and edge- Wise with respect to the shaft and to their retainer members, they may be said to be floatingly mounted.

.As a means for maintaining the discs in proper shearing relation it is desirable to provide a pair 'of'bearing members 3? which coact to force the interengaging portions of the discs together. The bearing members or shoes 37 preferably are 'in tl'ieform of small'rollers 38 which are journalled on rods'39 disposed to slide longitudinally in suitable guide openings in the supports [5. The-rollers '38 bear laterally against, and roll upon the outer faces of the end cutting discs, being arranged to contact such discs in the zone of the" overlapping portions thereof. Springs 40 on rods- 39-act upon the rollers 38 and provide the forces for holding the overlapping portions of the discs in lateral, shearing engagement with each other. 1 Suitable means (not shown) are preferably provided for rendering the pressure of springs 48, and hence disc contact pressures, adjustable; so that "the disccontact pressures may be'varied to adapt the apparatus to cut sheet material of different kind and thickness.

' In-operation, the material. to be cut, indicated "retainer members.

" It'is desired to point out that in the disc mountingarrangementfdescribed herein, the discs bear uponth'eir' associated retainer races at the outboard'sides of the shafts (note the location of contactpoint's 35, Fig. 2) and they contact the discs with:which they coact at the inboard sides of the shafts. Thus it will appear that the major contact' zones', of each'disc are relatively widely spaced and occur at relatively opposite sides of the shaft upon which the disc is mounted. This factor,-'it is believed, has great stabilizing effect on the loosely mounted discs.

While I havedescribed my invention with reference to a machine for cutting sheet material intostripsand which employs a multiplicity of clittingdiscs, the invention resides principally in the method. and means bywhich a cutting disc is looselymounted in a stabilized manner on a shaft or other rotating body. Obviously the means of the invention may be incorporated in cutting apparatusemploy-ing but two coacting discs for producing a single shear cut in sheet material, or inainachine" employing but a single cutting disc which is adapted to operate in edge-abutting relation ito a backing roll.

""" It"*will"also appear that various changes and i 3. In a machine 2,191,148 modifications may be made in the apparatus herein shown and described without departing from the spirit and full intended scopeof my invention as defined by the appended claims. i

. 1. In a machine for cutting sheet materialpa rotatable shaft, an annular cutting disc loosely disposed on said shaft, and a disc-retaining member fixed to the shaft, adapted to'impart shaft rotation to the disc, said member having a cage portion in loose, environing relation to an inner peripheral portion of said disc. i

r 2. In, a machine for cuttingsheet material, "a rotatable shaft, an annular cage'fixedto said shaft, and a cutting disc loosely retained on said shaft by said cage, said eutting disc being formed with a bearing portion loosely journalled within said cage;

said member having an annular journal-forming portion surrounding and loosely confining the bearing portion of said cutting disc.

.4. In a machinefor cutting sheet material, a

rotatable member having an annular flange. formed thereon, and a cutting disc having a cy- ,lindrical bearing portion disposed within and bearing on the inner surface of said flange, the

, inner diameter ,of said flange being appreciably greater than the diameter K of said disc.

of the bearing portion 5. In a machine for cutting sheet material, a rotatable shaft, an annular cutting disc loosely disposed about said shaft, said disc having an shaft for rotation therewith, said collar having i an annular undercut channel formed therein, an

annular, laterally projecting flnge thereon, an

annular retaining member fixed tosaid shaft, said;retaining member having a laterally projecting flange surrounding said disc flange, said retainer being adapted to hold said disc out of contact with the shaft, yet permitting translational movement of the disc relative thereto.

'6; In a machine for cutting sheet material, a

r rotatable shaft, an annular cutting tool disposed about said shaft, the internal diameter of said tool being substantially greater than the diameter of said shaft, said tool having an annular,

laterally projecting flange thereon, a member fixed to said shaft, said member having an annular portion surrounding said tool flange and forming a raceupon which the tool flange is adapted to roll. l 7. In a machine for cutting sheet material, a rotatable shaft, acollar fixedly secured to the annular cutting disc loosely mounted on said collar with its inner peripheral margin disposed within said channel, said disc having a lateral flange thereon fitting loosely within the undercut portion of said channel. 8. In a machine for cutting sheet material, a rotatable shaft, an annular cutting disc on said shaft, the internal diameter of said disc being substantially greater than the diameter of said shaft, and a disc-retaining member adapted. to impart shaft rotationrto the disc, said member having a cage portion fixed to said shaft disposed in loose, environing relation with an inner peripheral portion of the disc. e

9. In a machine for cutting sheet material, a rotatable shaft, an annular. cutting disc on said.

shaft, theinternal diameter of i said disc being r substantially greater than the diameter of said for cutting, sheet material, a circular cutting disc having means integral therewith forming a bearing portion, and a rotatable memberon which said disc is mounted,

shaft, and a disc-retaining member on the shaft adapted to impart shaft rotation to the disc, said retaining member having an annular cage-formin'gportion in loose, confining relation to an inner peripheral portion of said disc, said retaining member being adapted to; prevent contactbetween said disc and shaft.

10. In a machine for cutting sheet material, a rotatable shaft, an annular cutting disc on said shaft, the internal diameter of said disc being substantially greater than the diameter of said shaft, and a disc-retaining member fixed to the shaft and including a substantially, annular cage-forming portion, said disc having an inner peripheral portion floatingly confined within the cage-forming portion of said retaining member,

said retaining member preventing contact between said disc and shaft.

11. In a machine for cutting sheet material, a c

rotatable shaft, a collar fixed for rotation with said shaft and having an annular laterally projecting flange providing a race or bearing surface that faces toward the center of rotation, an annular. cutting disc floatingly retained on said shaft by said collar, said disc having an annular shoulder formed thereon, said shoulder being disposed within said flange and adapted for rolling contact with said bearing surface.

l2. Apparatus for cutting sheet material comprising a rotatable shaft, a plurality of annular cutting discs floatingly mounted on said shaft, a plurality of annular disc-retaining members fixed on the shaft for rotation therewith, said members being disposed between said discs and coacting to form annular, undercut channels adapted loosely to receive the discs, said discs having lateral flanges formed on their inner peripheries that extend into the undercutportions of said channels, the outer surfaces of said flanges being adapted for rolling contact on said members; a second set of cutting discs loosely mounted in the aforesaid manner on a rotatable shaft extending parallel to the first said shaft, the discs of the respective shafts, being disposed in intercalated laterally contacting relation. I

13. Apparatus forshearing sheet material comprising a rotatable shaft, a plurality of annular cutting discs floatingly carried by said shaft, the internal diameter of said discs being substantially greater than the diameter of the shaft, a plurality of disc-retaining members fixed for rotation with the shaft, each disposed between an adjacent pair of cutting discs, said discs having flanges projecting laterallyat the inner periphery thereof, said retaining members having lateral flanges disposed in overlapping relation to, andadapted to be engagedby said disc flange, said other; a plurality of annular cutting .discs loosely adjacent collar flanges, said discs having annular laterally projectingflanges thereon, said collar flanges having annular portions surrounding the disc flanges and providing a race upon which the flanges being axially spaced with respect to each i v disposed on said collars, each between a pair of discs are adapted to bear, said discs, being floatingly supported by said collars.

' 15. Apparatus for shearing sheet material com prising a rotatable shaft, a plurality of annular cutting discs disposed on said shaft,'the inner diameter of each of said. discs being substantially greater than the diameter of said shaft,.means' floatingly retainingthe discs on the shaft comprising a plurality of collars fixedyto the shaft,

each disposed between a pair of adjacent cutting discs, each of said collars having an. internal annular race or bearing surface formed thereon,

each of said discs havingai cylindrical bearing portion loosely confined within and adapted to bear radially outwardlyvupon the race of an aded to roll upon said race, the discs on'the respecends of thedisc assembly tending axially to comtive shafts'being disposed in overlapping engagement and coacting to shear material fed thereto.

17. A, machine for cutting sheet materialinto strips, a pair of parallel, rotatable shafts, a plu-f rality of cutting discs loosely disposed on saida;

shafts with the discs of onesha'ft extending be tween and adapted to coact laterally with the discs of the other shaft, a plurality of annular ,spac'er members on the shafts, each disposed between a pair of adjacent cutting discs,'said i:

cutting discs having annular, laterally projecting flanges formed near the inner periphery thereof,

said spacer members having annular, laterally projecting flanges formed near the outer periphery thereof, and disposed in overlapping rela;

tion with said disc flanges, said spacer flanges providing an internal race upon which the discs are adapted to roll, and means at theopposite press the assembled discs.

l8. A machine for cutting sheetmate'rialinto strips as set forth in claim 17 wherein the compression means at the opposite ends of the, disc assembly comprise resiliently mounted shoes disposed in bearing engagement with the end discs of the assembly, in registry with the interengag-' ing 'portionsof the coacting discs.

' ALBERT C. PERBAL. 

